Hi @Dr_Cole . Thanks for your detailed and thoughtful answer. But I just don't see how harvesting perifollicular adipose can be a realistic answer to anything. Where will this be harvested from? It seems to me, just as healthy terminal hair follicles are in short supply on the average balding man's head, so is perifollicular adipose. Will you be harvesting it from the legs, beard, and other places, along with the scalp? Because, just as the bottom line of hair transplantation has always been limited by donor supply of follicles on the scalp, I think you'll hit the same brick wall with a limited donor supply of perifollicular adipose in the scalp. The only valuable adipose tissue will be around healthy growing terminal follicles.
You're saying hair follicles develop as a combination of ectoderm and mesoderm which is very true. Then you said that adipose tissue comes from very far from mesoderm -- I assume you mean most of it comes from endoderm (the most inner portion of the developing embryo). First, I don't think it matters where the adipose tissue comes from -- what you need is the chemical signaling expressed by stem cells within the adipose tissue. This would be generally the same type of signaling whether the adipose comes from the vicinity of the follicles, or from abdominal adipose. (If you disagree with this, do you have any citations of studies which says otherwise?) Second, adipose tissue actually comes from both endoderm (a small amount) and mesoderm -- in fact, PRIMARILY from mesoderm. Please see the following article which says it comes from mesoderm:
So, if we go by what it says in that article, and you think it's important for adipose signaling to come from mesodermally-derived fat (because of the mesodermal connection with the hair follicle), then any fat should do, including abdominal fat.
Just my opinion...